Water-compatible urethane-containing amine hardener

ABSTRACT

A formulation to produce urethane linkages reacts cyclocarbonate groups with diamines. Aliphatic polyhydroxyl precursor molecules are first epoxidized. The invention does not require complete epoxidation, as it makes use of the unepoxidized hydroxyl groups of the precursor molecule. These hydroxyl groups are combined with isocyanate groups of prepolymer molecules to form urethane links. The use of prepolymers increases the networking, flexibility, and impact-resistance of the final product. The known formulations for amine hardeners also require complete carbonation of the epoxy groups to form reactive cyclocarbonate groups, which are reacted with diamines to form an amine hardener. In the proposed invention, both cyclocarbonate and epoxy groups are used to combine with the different diamine molecules by making use of the different reactivities of aliphatic, cycloaliphatic, and aromatic amine groups. This procedure not only increases the networking in the final polyurethane, it ensures that there are enough reactive amines to form the amine hardener. In addition, the resulting urethane contains hydroxyl groups which impart water-compatibility. The amine hardener can then be combined with any commercial epoxy resin to form a polyurethane that is water-compatible, non-toxic, has a low viscosity, and a high degree of penetrance into a surface, and after curing is impact-resistant, abrasion-resistant, chemical-resistant, strong, and flexible.

RELATED APPLICATIONS

[0001] This application is a divisional of application Ser. No.08/876,998 filed on Jun. 16, 1997.

FIELD OF THE INVENTION

[0002] This invention relates generally to polyurethane formulations.More particularly, it relates to a water-compatible urethane-containingamine hardener which produces a polyurethane when combined with an epoxyresin.

BACKGROUND OF THE INVENTION

[0003] Polyurethanes are high molecular weight compounds which have ahigh degree of strength, hardness, and friction resistance. They areoften used as adhesives, cements, and coatings. They are made ofpolymers which contain repeating urethane groups, as shown in FIG. 1.

[0004] Traditionally, polyurethanes may be produced by reacting diolswith di-isocyanates, as shown in FIG. 3. U.S. Pat. No. 4,401,499 byKaneko et. al discloses a method for producing a resin which reactsmolecules containing hydroxyl groups with di-isocyanates to formtemporary urethane polymers, which are noted for their stability andstrength. Isocyanates, however, are highly toxic, non-stable substancesbecause they react easily with water, such as moisture in the air. Thismethod of producing polyurethane cannot be used in many applications,namely those involving direct contact with water.

[0005] U.S. Pat. No. 5,175,231 by Rappoport, incorporated herein byreference, describes a method for producing water-compatiblepolyurethanes which involves reacting oligomeric cyclocarbonates withdiamines. This method begins with aliphatic polyepoxy molecules, whichare used as precursors for cyclocarbonate-containing molecules. Anexample is Heloxy 84® produced by Shell Chemical Company. This productcontains several epoxy functional groups. Since a desirable polyurethanecoating comprises molecules attached to each other in a non-dissipated,three-dimensional network, it is preferable to have a precursorcontaining as many multi-functional epoxy groups as possible. However,the aliphatic polyepoxy molecules normally contain a number of residualhydroxyl groups that were not converted to epoxy groups, as epoxidationof aliphatic molecules is never 100% efficient due to the nature of thereaction commonly used. As a result, there are fewer epoxy groupsavailable than desired, thus reducing the number of cyclocarbonategroups and possible links in the future polyurethane network. Althoughit is possible to increase the percentage of epoxy groups, it is moreexpensive and technically difficult to reach comprehensive epoxidationof aliphatic hydroxyl-containing compounds such as Heloxy 84®.

[0006] In Rappoport's method, the epoxy functional groups of Heloxy 84®are reacted with carbon dioxide to produce cyclocarbonate functionalgroups. The reaction is shown in FIG. 2. This reaction is also less than100% efficient, leaving some epoxy groups unreacted. Like the residualhydroxyl groups mentioned above, these unreacted epoxy groups reduce thefunctionality of the urethane molecule and as a consequence, the numberof links in the final polyurethane network. Typically, the conversionrate of epoxy groups to cyclocarbonate groups is only about 80-85%efficient at the soft conditions before “sticking” of the carbonationreaction occurs. In order to achieve comprehensive carbonation, a moreextreme version of the reaction must be carried out. The temperature israised from 100° C. to 130° C., the reaction time is increased from1-1.5 hours to 5-6 hours, and a larger amount of catalyst, usuallyquaternary ammonium salts, is used. Though this reaction ensures thatnearly all the epoxy groups have been turned into cyclocarbonate groups,it also produces undesirable side reactions and products. In addition,it is more expensive and time-consuming.

[0007] After the formation of cyclocarbonate functional groups, themolecules are reacted with diamines, such as Vestamine IPD (isophoronediamine) and Vestamine TMD (trimethyl hexamethylene diamine), both madeby Hüls America, Inc. The reaction is shown in FIG. 4. These diaminescontain two amine groups with different reactivities. For the isophoronediamine, the aliphatic amine groups are the more reactive amines, whilethe cycloaliphatic amine groups are the less reactive amines. The morereactive aliphatic amines are usually used to react with thecyclocarbonate groups of the molecules, thus forming urethane links. Theless reactive cycloaliphatic amines are left unreacted. The urethanelinks form the basis for the urethane-containing amine hardener. Theamine hardener is usually packaged and stored until it is time to createthe polyurethane.

[0008] In order to create the polyurethane, the urethane-containingmolecules of the amine hardener containing the unreacted less reactivecycloaliphatic amines are combined with an epoxy resin. These lessreactive cycloaliphatic amines react with the epoxy resin to form thepolyurethane. The polyurethane is then cured as a result of thehardener's multifunctionality. Unfortunately, because all the morereactive amine groups have previously reacted, there is often a shortageof less reactive amine groups in the curing stage which leaves thereaction incomplete and weakens the structure of the final polyurethane.

[0009] In many epoxide resin-amine hardener formulations, reactions arecarried out in the presence of organic solvents, which are volatile airpollutants and sometimes carcinogenic. These organic solvents alsodecrease the reactivity of the functional groups, thus reducing thedegree of cross-linking.

OBJECTS AND ADVANTAGES OF THE INVENTION

[0010] Accordingly, it is the primary object of the present invention toimprove the efficiency and lower the cost of amine hardener formulationsand to overcome problems due to the incomplete epoxidation andcarbonation reactions. It is another object of this invention to providea variety of amine hardeners by formulating different combinations ofthe necessary structural units, which also allows control over theproperties of the polyurethane to be produced. It is another object ofthe invention to remove hazardous components from the presence ofpolyurethane users at the final processing stage. Another object of theinvention is to produce a superior polyurethane formulation, which iswater-compatible, non-toxic, has a low viscosity, and has a high degreeof penetrance into a surface (mainly porous) before curing, and isimpact-resistant, abrasion-resistant, chemical-resistant, strong, andflexible after curing. It is a final object of the invention to providea one-package polyurethane formulation, whereby the urethane-containingamine hardener and epoxy resin can be packaged together for a certainamount of time without reacting until needed.

SUMMARY OF THE INVENTION

[0011] These objects and advantages are attained by an improvedurethane-containing amine hardener synthesis. Precursor aliphaticpolyepoxies, such as Heloxy 84®, contain a plurality of epoxy functionalgroups, as well as residual hydroxyl functional groups that were notconverted to epoxy groups at the time of the Heloxy 84® synthesis frompolyepoxy molecules. The proposed formulation for amine hardenersynthesis makes use of the unconverted hydroxyl groups by reacting themwith isocyanate groups on a prepolymer molecule to form aurethane-containing molecule. Although this reaction contains hazardouscomponents, it is achieved under the supervision of specialists insealed chemical equipment. Polyurethane users are not exposed to anychemical hazards.

[0012] As a result of the above modification, the epoxy-containingmolecules bearing the mentioned hydroxyl groups are combined together byuse of the prepolymer molecule. Consequently, the common functionalityof the mixture is increased and a more complete, non-dissipated,three-dimensional network can be created at the curing stage. As isdescribed in the known method, the epoxy groups are reacted with carbondioxide to form cyclocarbonate groups. If this reaction is carried outat the more soft conditions, it is 80-85% efficient, thus leaving someepoxy groups unconverted. The proposed formulation for amine hardenersis able to make use of the unreacted epoxy groups by taking advantage ofthe different reactivities of diamine molecules, cyclocarbonatemolecules, and epoxy molecules. Aliphatic amines have a high reactivityto both cyclocarbonate and epoxy functional groups, as shown in FIGS. 5and 6. Cycloaliphatic amines have a lower reactivity but are still ableto react with both cyclocarbonate and epoxy functional groups, as shownin FIGS. 7 and 8. Aromatic amines are the least reactive, as they areonly able to react with epoxy functional groups, as shown in FIG. 9, butnot with the cyclocarbonate groups. Thus, selectively reacting thearomatic amine groups with the unconverted epoxy groups on the urethanemolecule renders them functional, but does not affect the cyclocarbonategroups. This reaction produces functional amine-containing moleculeswhich are indifferent to cyclocarbonate groups at the ambienttemperature, so that the two can coexist. However, after the addition ofthe epoxy resin to form the final polyurethane, the aromatic amines willbe able to participate in the curing process.

[0013] The different reactivity of the amines is also used in the finalstage of urethane-containing amine hardener synthesis. Modified diaminesare used instead of the “virgin” ones used in the known method. Byblocking the more reactive aliphatic amine groups of the isophoronediamine with a ketone, thus forming an amino-ketoxime, as shown in FIG.10, it is possible to allow the less reactive cycloaliphatic aminegroups to react with the cyclocarbonate functional groups first.Interior urethane links are formed in this way. These molecules arestable and can be kept for a certain amount of time until thepolyurethane is produced, due to the “hidden” more reactive aliphaticamine groups. These molecules also contain “hidden” hydroxyl groups nearthe urethane links which impart water-compatibility to the finalhardener as a result of the urethane reaction.

[0014] To produce the final amine hardener which can react with an epoxyresin, the more reactive aliphatic amine groups must be deprotected.This is easily achieved with hydrolysis by water to remove the ketones.The regenerated more reactive aliphatic amine groups can then react withthe epoxy functional groups of the epoxide resins. Any commercialaromatic epoxy resin may be used. In addition, the resulting aminehardener may be used in combination with other commercial polyaminehardeners such as di-ethylene-triamine or amino-amides to form aminehardeners with different characteristics.

[0015] The final amine hardener can be combined with an epoxy resin toform an especially water-compatible formulation which possessesimpact-resistance, abrasion-resistance, chemical-resistance, strength,and flexibility after curing. This nontoxic polyurethane has a lowviscosity and a high degree of penetrance into a surface, and as suchcan be used to coat, protect, and repair concrete, cement, wood, gypsum,and other porous surfaces. It can also be used for impregnation andreinforcement. Other uses include water-diluted coatings for wood andwater-borne adhesives for silicate materials. Curing can take place atthe ambient temperature. Polyurethane coatings produced by thisinvention are especially strong and flexible, due to the incorporationof the prepolymer molecules which form additional links in the finalnetwork, as well as increasing the functionality of the amine hardener.

[0016] In addition, the ability of this invention to make use of allthree cyclocarbonate, epoxy, and hydroxyl functional groups not onlyincreases the number of links in the final complete network, but alsoreduces time and cost factors in the synthesis of urethane-containingamine hardeners and the processing of amine hardener-epoxy resinformulations.

DESCRIPTION OF THE FIGURES

[0017]FIG. 1 shows the chemical structure of a urethane link.

[0018]FIG. 2 is a reaction diagram between an epoxy group and carbondioxide to produce a cyclocarbonate-containing molecule.

[0019]FIG. 3 is a reaction diagram between an oligodiol and adiisocyanate to form a polyurethane. This is the known method.

[0020]FIG. 4 is a reaction diagram between a cyclocarbonate group and adiamine molecule to form a water-compatible, hydroxyl-containingpolyurethane without the use of diisocyanates.

[0021]FIG. 5 is a reaction diagram between an aliphatic amine group anda cyclocarbonate group to form a urethane linkage.

[0022]FIG. 6 is a reaction diagram between an aliphatic amine group andan epoxy group to form a secondary amine linkage.

[0023]FIG. 7 is a reaction diagram between a cycloaliphatic amine groupand a cyclocarbonate group to form a urethane linkage.

[0024]FIG. 8 is a reaction diagram between a cycloaliphatic amine groupand an epoxy group to form a secondary amine linkage.

[0025]FIG. 9 is a reaction diagram between an aromatic diamine and anepoxy group to form an amine-containing molecule.

[0026]FIG. 10 is a reversible reaction diagram between an aliphaticamine group and a ketone to form an amino-ketoxime.

DETAILED DESCRIPTION

[0027] The proposed formulation for a urethane-containing amine hardenerto be combined with an epoxy resin to form a polyurethane begins with analiphatic polyepoxy precursor molecule that typically has not beencompletely epoxidized. This molecule may contain any number of bothepoxy and hydroxyl functional groups. Examples of such a moleculeinclude Heloxy 84® from Shell Chemical Company, or any otherepoxy-containing polyether typically having molecular weight 500-2000,functionality of 2.5-4.0, and containing 10-20% residual hydroxyl groupsafter incomplete epoxidation of corresponding polyhydroxylatedprecursors. The following steps are then carried out:

[0028] I. The epoxy functional groups of the aliphatic polyexpoxyprecursor molecules are reacted with carbon dioxide to formcyclocarbonate functional end groups, as shown in FIG. 2. Reactionconditions are roughly at a temperature of 110° C. for 1-1.5 hours, withthe addition of a catalyst, usually quaternary ammonium salts. Underthese reaction conditions, complete carbonation of the epoxy groups willnot occur, so some epoxy groups will remain unreacted. Efficiency isestimated at 80-85%. The resulting product contains both unconvertedepoxy and hydroxyl functional groups.

[0029] II. The residual hydroxyl functional groups of thecyclocarbonate-containing intermediates are combined with isocyanategroups of isocyanated prepolymer molecules to form urethane molecules,as shown in FIG. 3. By using prepolymer molecules with at least twoisocyanate groups, it is possible to combine two hydroxyl-containing,cyclocarbonate-containing molecules, thus creating a tetra-functionalurethane polymer from two bi-functional molecules. Examples of such aprepolymer molecule include any commercial polymers based on polyethers,polyesters, mixed poly (ethers-esters), or oligodienediols withmolecular weight of 500-2000. This reaction is carried out usingtraditional polyurethane chemistry under controlled conditions bytrained specialists. The polyurethane users are not in any wayassociated with this reaction.

[0030] III. The residual epoxy groups of the urethane molecules are madefunctional by combining them with aromatic diamine molecules to formamine-containing urethane molecules. Examples of such aromatic diaminemolecules are methylene-bis-orto-aniline and its substitutedderivatives. The aromatic amines are relatively unreactive and as such,do not react with the cyclocarbonate groups. However, they participatein the reaction with the epoxy groups of the epoxy resin later on.

[0031] IV. At this point, the cyclocarbonate groups of the intermediatemolecules are reacted with diamine molecules containing amine groupswith different reactivities to form a functional amine hardener, asshown in FIGS. 5 and 7. An example of such a diamine molecule is anisophorone diamine containing more reactive aliphatic groups and lessreactive cycloaliphatic groups. To create an amine hardener withincreased reactivity, a preliminary modification of the diamine moleculeis made. The more reactive aliphatic amine groups are protected by useof a ketone to produce an amino-ketoxime, as shown in FIG. 10. Anexample of such a ketone is methyl ethyl ketone. The less reactivecycloaliphatic amine groups are left unmodified.

[0032] V. The cyclocarbonate functional groups of the urethane moleculesare now able to combine with the unprotected less reactivecycloaliphatic amine groups to form an amine hardener, as shown in FIG.7. The urethane linkages produced by the reaction between thecyclocarbonate groups and the above amines contain hydroxyl groups thatimpart water-solubilty to the final polyurethane. The resultingurethane-containing amine hardener is stable and can be packaged andstored under dry conditions until needed.

[0033] VI. When it is time to form the final cured polyurethane, themore reactive aliphatic amine groups are regenerated, as shown in FIG.10. The amino-ketoxime may be hydrolyzed and destroyed by addition ofwater. A much larger volume of water than neccesary to destroy theamino-ketoxime may be used.

[0034] VII. With the addition of an epoxy resin, this amine hardener cannow form the polyurethane. Any commercial aromatic epoxy resin may beused. In addition, the resulting amine hardener may be used incombination with other commercial polyamine hardeners such asdi-ethylene-triamine or amino-amides to form amine hardeners withdifferent characteristics.

[0035] Using the method described above, it is clear that a stable,long-lasting, one-package polyurethane kit can be produced. Such a kitwill contain urethane polymers produced by the described method, anepoxy resin, and a hydrolytic substance. This kit can be stored for afew days under dry conditions and then be transported to the site wherethe polyurethane is to be constructed.

EXAMPLES Example 1

[0036] Polyglycidyl ether of an aliphatic polyol with a structure ofpolyoxypropylene, tradename Heloxy 84® (Shell Chemical Company, CASNumber 37237-76-6) having a molecular weight of 620-680 per epoxy group,with a calculated molecular weight approximately of 1700, functionalityequal to 3 according to the chemical formula, with an amount of residualnon-epoxidized hydroxyl groups up to 15%, is used as the main precursorfor the urethane-containing amine hardener synthesis.

[0037] 500 grams of the above mentioned product are loaded into amicroreactor with a volume of 1 liter, provided with an effectiveagitator and heater. 1 gram of quaternary ammonium salt catalyst such asn-alkyl di-(methyl)-benzyl ammonium chloride (Mason Chemical Company,The Quaternary Specialists) or tetra(butyl) ammonium bromide (ZeelandChemicals, Inc.) is added.

[0038] Dry carbon dioxide is introduced into the reactor up to apressure of 150 lb/square inch. A temperature of 240° F. is maintainedfor the carbonation process.

[0039] Periodically, assays from the reactor are analyzed to estimatethe decrease of epoxy groups. Their conversion into carbonate groups iscalculated. After 2 hours, a conversion of 85% is reached.

Example 2

[0040] 502 grams of the carbonated oligomer as described in EXAMPLE 1are mixed with 83.6 grams of an isocyanated prepolymer with a backbonestructure of poly(oxytetramethylene), molecular weight appoximately1,000, containing 7.8% isocyanate groups, tradename Andur 75-DCP-2(Anderson Development Company). 0.4 grams of di-butyl-dioctate of tinare added as a catalyst. The reaction between the two components iscarried out at 120° F. for 2 hours until the content of isocyanategroups is close to zero.

[0041] 157.4 grams of tri-methyl-hexamethylene diamine (80% solution inwater), tradename Vestamin TMD (Hüls America) is mixed with theintermediate above. The reaction is carried out at 100° F. for 1 hour.

[0042] The resulting urethane-containing amine hardener has thefollowing properties:

[0043] % amine groups: 4.8

[0044] viscosity (Brookfield, 50° F.): 800 poises (2 rpm)

[0045] The hardener can be mixed with 10% water for a transparentmixture formation.

Example 3

[0046] 230 grams of the amine hardener described in EXAMPLE 2 are mixedwith 100 grams of an aromatic epoxide resin with Epoxide Number 190,tradename Epon 828 (Shell Chemical Company) at the ambient temperature.20 grams of water are added. The mixture of hardener, Epon 828, andwater is transparent. It can penetrate into concrete to a depth of 2-4mm, depending on the type of concrete.

[0047] The mixture is left at the ambient temperature for 24 hours.After the first 2 hours, the mixture begins to harden.

[0048] Testing of the hardened samples is made after 7 days. The curedpolymer has the following properties:

[0049] hardness (shore A/D): 75/24

[0050] adhesion to concrete: >600 p.s.i.

[0051] tensile strength: 1400 p.s.i.

[0052] elongation at the break: 67%

[0053] flexural modulus: 4800 p.s.i.

[0054] Chemicals immersion test—% weight gain after 24 hours at 50° F.:

[0055] water: 0.8

[0056] 10% sulfuric acid: 1.2

[0057] 50% sodium hydroxide: 0.07

[0058] 20% sodium chloride: 0.9

[0059] methyl ethyl ketone: 38.9

[0060] toluene: 18.5

[0061] mineral oil: 0.27

Example 4

[0062] 124 grams of the hardener described in EXAMPLE 2 are mixed with5.4 grams of the commercial hardener di-ethylene-triamine (DETA, BASFCorp.) and then with 90 grams of Epon 828 and 10 grams of Heloxy 48®(both from Shell Chemical Company).

[0063] After complete curing at the ambient temperature for 7 days, thefinal product has the following properties:

[0064] hardness (Shore D): 55

[0065] tensile strength: 1500 p.s.i.

[0066] elongation: 35%

[0067] Young's modulus: 11 k.s.i.

[0068] flexural modulus: 20500 p.s.i.

Example 5

[0069] As in EXAMPLE 4, 83 grams of urethane-containing amine hardener,7.3 grams of DETA, and 90/100 grams of Epon 828/Heloxy 48® are combined.

[0070] The cured polymer has the following properties:

[0071] hardness (Shore D): 70

[0072] adhesion to concrete: >600 p.s.i.

[0073] tensile strength: 2700 p.s.i.

[0074] elongation: 26%

[0075] Young's modulus: 46 k.s.i.

[0076] flexural modulus: 73500 p.s.i.

Example 6

[0077] A polymer is made by mixing the same components as in theprevious example, using the following masses: 46, 8.7, 90, 10.

[0078] The cured polymer has the following properties:

[0079] hardness (Shore D): 82

[0080] adhesion to concrete: >600 p.s.i.

[0081] tensile strength: 4500 p.s.i.

[0082] elongation: 13%

[0083] Young's modulus: 100 k.s.i.

[0084] flexural modulus: 145000 p.s.i.

Example 7

[0085] A polymer is made by mixing the same components as in theprevious example, using the following masses: 38, 9.1, 90, 10.

[0086] The cross-linked polymer has the following properties:

[0087] hardness (Shore D): 82

[0088] adhesion to concrete: >600 p.s.i.

[0089] tensile strength: 4800 p.s.i.

[0090] elongation: 15%

[0091] Young's modulus: 120 k.s.i.

[0092] flexural modulus: 170000 p.s.i.

Example 8

[0093] 76 grams of the same urethane-containing amine hardener and 23grams of the commercial hardener Jeffamine 230 (Huntsman Corp.) arereacted in combination with an epoxy mixture consisting of 90 grams Epon828 and 10 grams Heloxy 48®.

[0094] After curing the polymer has the following properties:

[0095] hardness (Shore D): 70

[0096] tensile strength: 2630 p.s.i.

[0097] elongation: 60%

[0098] Young's modulus: 55 k.s.i.

[0099] flexural modulus: 70000 p.s.i.

Example 9

[0100] The mixture of hardeners described in the previous exampleconsisting of 46/28 grams is used in combination with the same amount ofepoxies.

[0101] The cured polymer has the following properties:

[0102] hardness (Shore D): 78

[0103] adhesion to concrete: >600 p.s.i.

[0104] tensile strength: 4000 p.s.i.

[0105] Young's modulus: 110 k.s.i.

[0106] flexural modulus: 175000 p.s.i.

Example 10

[0107] The mixture of hardeners described in the previous exampleconsisting of 32/30 grams is used in combination with the same amount ofepoxies.

[0108] The cured polymer has the following properties:

[0109] hardness (Shore D): 82

[0110] adhesion to concrete: 5500 p.s.i.

[0111] elongation: 12%

[0112] Young's modulus: 160 k.s.i.

[0113] flexural modulus: 222000 p.s.i.

Example 11

[0114] 89.4 grams of carbonated Heloxy 84® made as described in EXAMPLE1 are mixed with 14.3 grams of isocyanated prepolymer Andur-2-90 AP,molecular weight approximately 2200, containing 4.15% isocyanate groups(Anderson Development Co.)

[0115] 0.06 grams of tin organic catalyst is added to the mixture. Afterinteraction at 120° C. for 2 hours, no isocyanate groups are detected inthe intermediate product. The product is then mixed with 58.6 grams ofisophorone diamine (80% solution in water), tradename Vestamin IPD (HülsAmerica).

[0116] After 1 hour at 120° F. the hardener has a viscosity of 530poises (at 50° F.) and contains 4.26% amine groups.

Example 12

[0117] 100 grams of urethane-containing amine hardener are madeaccording to EXAMPLE 11 and mixed with 100 grams of Epon 828 and curedat the ambient temperature.

[0118] Solidification occurs after approximately 3.5 hours.

[0119] The cured polymer has the following properties:

[0120] hardness (Shore D): 83

[0121] adhesion to concrete: >600 p.s.i.

[0122] tensile strength: 4300 p.s.i.

[0123] elongation: 15%

[0124] Chemicals immersion test—% weight gain after 24 hours, 50° F.:

[0125] water: 0.49

[0126] 10% sulfuric acid: 0.8

[0127] 50% sodium hydroxide: 0.23

[0128] 20% sodium chloride: 0.38

[0129] toluene: 4.0

[0130] mineral oil: 0.2

Example 13

[0131] Heloxy 84® is carbonated as in the procedure described in EXAMPLE1, but only up to 73% conversion of epoxy groups. 76 grams of theproduct are mixed with 11.5 grams of aromatic diamine, tradenameLonzacure M-CDEA (Lonza). After 4 hours at 160° F., analysis shows anabsence of the epoxy groups.

[0132] The resulting product is reacted with 34.6 grams of Vesamin IPD(80% solution in water) at 120° F. for 2 hours.

[0133] The amine hardener has the following properties:

[0134] % amine groups: 3.5

[0135] viscosity: 530 poises

Example 14

[0136] 80 grams of hardener made according to EXAMPLE 13 are mixed with100 grams of Epon 828.

[0137] After complete curing at the ambient temperature for 7 days, thefinal product has the following properties:

[0138] hardness (Shore D): 80

[0139] tensile strength: 1500 p.s.i.

[0140] elongation: 35%

[0141] Young's modulus: 29 k.s.i.

[0142] flexural modulus: 7000 p.s.i.

[0143] Chemicals immersion test:

[0144] water: 0.45

[0145] 10% sulfuric acid: 0.8

[0146] 50% sodium hydroxide: 0.25

[0147] 20% sodium chloride: 0.25

[0148] toluene: 23.0

[0149] mineral oil: 0.17

Example 15

[0150] 64.7 grams of oligomer with 73% carbonation of epoxy groups isreacted with 10.2 grams of Lonzacure M-CDEA. 29.2 grams of Vestamin TMD(80% aqueous solution) are added.

[0151] The complete urethane-containing amine hardener has the followingproperties:

[0152] % amine groups: 3.5

[0153] viscosity: 85 poises

Example 16

[0154] A Heloxy 84® with 90% carbonation of epoxy groups is produced byusing the procedure of EXAMPLE 1 with the reaction time increased to 5.5hours. 84.7 grams of the obtained product are mixed with 14 grams of theisocyanated prepolymer Andur 2-90 AP and 0.06 grams of tin catalyst.After the isocyanate groups disappeared, 54.2 grams of Vestamin TMD (80%aqueous solution) were added and reacted according to the describedconditions.

[0155] The amine hardener has the following properties:

[0156] % amine groups: 4

[0157] viscosity: 75 poises.

Example 17

[0158] 100 grams of hardener made accoring to EXAMPLE 16 were mixed with100 grams of Epon 828 and cured completely at the ambient temperaturefor 7 days.

[0159] The polymer has the following properties:

[0160] hardness (Shore D): 70

[0161] tensile strength: 2700 p.s.i.

[0162] elongation: 40%

[0163] flexural modulus: 44500 p.s.i.

[0164] This polymer possesses excellent stability despite UV radiationand remains colorless 6 months after exposure to sun radiation. A fewcommercial formulations made with Epon 828 have turned an intense yellowcolor under the same conditions.

[0165] Chemicals immersion test:

[0166] water: 0.6

[0167] 10% sulfuric acid: 1.2

[0168] 50% sodium hydroxide: 0.35

[0169] 20% sodium chloride: 0.4

[0170] methyl ethyl ketoe: 28.0

[0171] toluene: 6.0

[0172] mineral oil: 0.09

Example 18

[0173] Isophorone diamine (Vestamin IPD) is reacted with methyl ethylketone to form an amino-ketoxime. 34 grams of the above diamine areplaced in a sealed reactor under dry conditions (under argon atmosphere)and cooled to a temperature of approximately 40° F. 15 grams of methylethyl ketone are dosed into the diamine gradually, by separate drops, toavoid a rise in temperature. After methyl ethyl ketone dosing, theproduct of the reaction has been exposed to the ambient temperature for1 hour. The urethane-containing amine hardener is synthesized under theconditions of EXAMPLE 11, but 85 grams of amino-ketoxime is used insteadof the individual dosing of Vestamin IPD. This interaction requires 2.5hours. The hardener with hidden reactive amine groups has a viscosty of150 poises.

Example 19

[0174] 105 grams of the hardener of EXAMPLE 18 are mixed with 100 gramsof Epon 828. This reactive mixture is stored in a sealed vessel atambient temperature. No essential change in viscosity is found after 3days of storage. 2 grams of water are added to 100 grams of the reactivemixture and carefully remixed. Solidification is detected after 1 hour.

What is claimed is:
 1. A method of preparing a water-compatibleurethane-containing amine hardener comprising the steps of: a) producingcyclocarbonate-containing, hydroxyl-containing intermediate molecules byreacting carbon dioxide with aliphatic epoxy-containing,hydroxyl-containing molecules; b) producing urethane molecules byreacting said cyclocarbonate-containing, hydroxyl-containingintermediate molecules with isocyanate-containing prepolymer molecules;c) producing the amine hardener by reacting said urethane linked,cyclocarbonate-containing, hydroxyl-containing intermediate moleculeswith diamine molecules.
 2. The method of claim 1 whereby said urethanemolecules are produced by reacting said hydroxyl groups with saidisocyanate-containing prepolymer molecules at a ratio of 1 hydroxylgroup:1 isocyanate group at 50-60° C. in the presence of 0.01-0.1%catalysts such as organic tin compounds or tertiary amines.
 3. Themethod of claim 1 further comprising the step of producingcyclocarbonate-containing, epoxy-containing, hydroxyl-containingmolecules by reacting carbon dioxide with said epoxy-containing,hydroxyl-containing molecules.
 4. The method of claim 3 whereby saidreaction occurs at 105-110° C. for 1-2 hours in the presence ofcatalysts such as quaternary ammonium salts amounting to 0.1-0.5% of themass, allowing 80-85% conversion of epoxy groups to cyclocarbonategroup.
 5. The method of claim 3 further comprising the step of reactinghydroxyl-containing molecules with isocyanate-containing prepolymermolecules to produce a second group of urethane-containing molecules. 6.The method of claim 3 further comprising the step of producingamine-containing molecules by reacting epoxy-containing molecules witharomatic amine molecules.
 7. The method of claim 6 whereby said reactionis carried out at a ratio of 1 epoxy group:2 aromatic amine groups. 8.The method of claim 3 further comprising the step of reactingcyclocarbonate-containing molecules with diamine molecules to produce athird group of urethane-containing molecules.
 9. The method of claim 8wherein said diamine molecules contain aliphatic amino groups withdifferent reactivities.
 10. The method of claim 9 further comprising thestep of temporarily protecting the more reactive aliphatic amino groupsby a ketone to form an amino-ketoxime.
 11. The method of claim 10whereby said step uses the ratio of 1 more reactive aliphatic aminogroup: 1 ketone molecule, using an isophorone diamine or a trimethylhexamethylene diamine, and a methyl-ethyl ketone, under dry conditionsat a temperature of approximately 0° C.
 12. The method of claim 9further comprising the step of producing urethane links by reacting saidless reactive aliphatic amines of amino-ketoxime withcyclocarbonate-containing molecules.
 13. The method of claim 12 wherebysaid step uses the ratio of 1 less reactive aliphatic amine group ofamino-ketoxime:1 free cyclocarbonate group, under dry conditions at atemperature of no more than 50° C.
 14. The method of claim 9 furthercomprising the step of reacting said amino-ketoximes with water toregenerate said more reactive aliphatic amines and said ketones.
 15. Anamine hardener made according to the method of claim 1 .